Fermi-LAT detection of another rapid GeV flare from the blazar PKS 1510-089
ATel #1897; S. Ciprini (Univ. Perugia & INFN Perugia), S. Corbel (CEA Saclay); on behalf of the Fermi Large Area Telescope Collaboration
on 9 Jan 2009; 19:51 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Stefano Ciprini (firstname.lastname@example.org)
Subjects: Gamma Ray, >GeV, AGN, Quasar, Transient
The Large Area Telescope (LAT), one of two instruments on the Fermi Gamma-ray
Space Telescope (formerly GLAST, launched June 11, 2008), has observed, since
January 08, 2009, a rapid flare from a gamma-ray source positionally consistent
with the blazar PKS 1510-089 (RA:15h12m50.5329s, Dec:-09d05m59.828s, redshift
0.360 and already known as an EGRET gamma-ray source, 3EG J1512-0849).
Preliminary analysis indicates that the sourceÂ isÂ in a high state
with a gamma-ray flux (E>100MeV)Â exceeding the pre-defined LAT flaring
source reporting threshold of 2x10^-6 photons cm^-2 s^-1.Â Â This is the
second time that Fermi is observing andÂ announcing a similar GeV flare in
this blazarÂ (September 2008, ATEL#1743)
that was also well detected previously in 2008 by AGILE (ATEL#1436).
During the first hours of January 09, 2009 there are hints for a fading, but
based on the previous gamma-ray behavior monitored by Fermi LAT in the past
months, the current activity state and brightnessÂ providesÂ chances forÂ further
fast flares in the next days.Â
This blazar is classified as a Flat Spectrum Radio Quasar (FSRQ), and is
rather bright at optical bands, allowing an easier ground-based follow up.
Because Fermi operates in an all-sky scanning mode, regular gamma-ray
monitoring of this source will continue. PKS 1510-089 is one of the "LAT
Monitored Sources", and consequently, a preliminary, uncalibrated
estimation of the daily gamma-ray flux observed by Fermi LAT is publicly
available. In consideration of the ongoing activity of this source we
strongly encourage multiwavelength observations. For this source the Fermi LAT
contact person is A. Tramacere (email@example.com).
The Fermi LAT is a pair conversion telescope designed to cover the energy
band from 20 MeV to greater than 300 GeV. It is the product of an international
collaboration between NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.